I am sure most of you felt the earthquake earlier this week, and I suspect that this was the first one for most of us. (not counting any west coast or international transplants of course) It was disconcerting at best for most, and downright scary for some. Here are a couple of thoughts for all of you.
Buildings in this area have usually been driven by loads from snow and wind. The more recent building codes however frequently point to seismic (earthquake) loads as the governing load for horizontal type forces instead of wind. Older buildings of course are hit or miss, as many predate building codes, and even those that don’t had very limited inspections done to verify compliance
Does this mean we should all panic and run into the streets? No. The reality is that most buildings have substantial capacity to resist this type of load, and what felt very noticeable to our highly sensitive feet and rear ends (if you were sitting), does not necessarily translate into high loads on your buildings. Flexible buildings tend to experience less load than rigid ones, and if we hear of damage anywhere, my suspicion is that it will be in some of the unreinforced brick and block buildings where the materials are very stiff, but also brittle. Houses, steel framed buildings, and other frame type construction will be unlikely to have seen any damage. I would suspect that as you get closer to Virginia, where the epicenter was, it will be more noticeable.
If nothing else, it was kind of exciting and broke up our afternoons. If we can be of any assistance to anyone, or just help with any questions, please feel free to call or email
Josh Carney, P.E.